Vaccine adjuvant-induced inflammation augments vaccine immunity in part by recruiting antigen presenting myeloid cells (monocytes and neutrophils) to vaccine draining lymph nodes (LNs) (Serafini et al. (2004) Cancer Res. 64:6337-6343; Martino et al. (2010) J. Immunol. 184: 2038-2047). However, recent evidence indicates that monocyte recruitment to LNs suppresses local B cell and T cell activation and proliferation (Mitchell et al. (2012) J. Immunology 189: 5612-5621; Mitchell et al. (2012) Int. Immunopharmacol. 15: 357-363). Lowered immune responses following vaccination can lead to decreased vaccine efficacy.
Moreover, the role of immature and immune suppressive myeloid cells, including neutrophils, monocytes, and tumor-associated macrophages, in promoting the growth of primary tumors is well established1-10. Additionally, myeloid cells, and especially monocytes play an important role in creating favorable conditions for the seeding and growth of tumor metastases in the lungs, in part by establishing the so-called metastatic niche15-17. Inflammatory monocytes recruited in response to tumor-derived signals have been shown to play a key role in promoting the growth of tumor metastases. The major chemokine regulating monocyte recruitment is MCP-1 (CCL2), which signals primarily via activation of the receptor CCR2 expressed principally on inflammatory monocytes.
What are needed in the art, are methods for administering vaccines and related vaccine compositions that enhance the immune response to an antigen and augment vaccine efficacy by inhibiting the suppressive effects of monocytes at LNs and enhancing B cell and T cell responses. What is also needed in the art, are methods for inhibiting the migration of myeloid cells, and in particular inflammatory monocytes, to the site of tumors where they act to promote tumor growth and metastasis. The present invention is directed to overcoming these deficiencies in the art.